The technology of the present disclosure relates to an image forming apparatus, and more particularly, to a technology for optimizing fixing temperature.
In an electrophotographic image forming apparatus, various image formation conditions, such as an applied voltage of an internal mechanism or a charging device, a developing bias voltage, a transfer voltage, and fixing temperature, are set such that an output image is optimized. Similarly, toner for development (hereinafter, simply referred to as “toner”) is also set corresponding to respective image forming apparatuses such that an output image is optimized. In recent years, as image forming apparatuses, a wide variety of apparatuses have been developed and sold commercially in response to the use of users such as a full color apparatus, a monochrome apparatus, and an image formation speed. Accordingly, toner has also been diversified.
There has been proposed a technology in which for fixability of a tone image to a recording paper which is one of qualities of an image forming apparatus, at the time of exchange of a toner container, a fixability test image is formed, the fixability test image having passed through a fixing device is rubbed with a rubbing roller, and fixability is evaluated from the difference of image density between a rubbed part and a non-rubbed part, so that fixing temperature of the fixing device is adjusted. Furthermore, there has been proposed a fixability evaluation technology in which the fixability is evaluated using a smear measuring apparatus serving as a detection means of the fixability and fixing conditions such as a nip width and fixing temperature are changed.